The wearable user device market has emerged and is expected to grow rapidly. Haptics may play a large role in the communication of information to users via wearable devices, which may be non-visual or may enhance the visual aspect of the device the user is interacting with. Typical inertial actuators, such as Eccentric Rotating Mass (“ERM”) actuators, are mounted in a rigid casing and create a range of vibration frequencies and magnitudes that can be conveyed to a user of a user interface device, such as a cellular phone or a smartphone.